Abel was a keeper of sheep – Genesis 4:2
As a shepherd Abel sanctified his work to the glory of God, and offered a sacrifice of blood upon his altar, and the Lord had respect unto Abel and his offering. This early type of our Lord is exceedingly clear and distinct. Like the first streak of light which tinges the east at sunrise, it does not reveal everything, but it clearly manifests the great fact that the sun is coming. As we see Abel, a shepherd and yet a priest, offering a sacrifice of sweet smell unto God, we discern our Lord, who brings before his Father a sacrifice to which Jehovah ever hath respect. Abel was hated by his brother–hated without a cause; and even so was the Saviour: the natural and carnal man hated the accepted man in whom the Spirit of grace was found, and rested not until his blood had been shed. Abel fell, and sprinkled his altar and sacrifice with his own blood, and therein sets forth the Lord Jesus slain by the enmity of man while serving as a priest before the Lord. “The good Shepherd layeth down his life for the sheep.” Let us weep over him as we view him slain by the hatred of mankind, staining the horns of his altar with his own blood. Abel’s blood speaketh. “The Lord said unto Cain, The voice of thy brother’s blood crieth unto me from the ground.'” The blood of Jesus hath a mighty tongue, and the import of its prevailing cry is not vengeance but mercy. It is precious beyond all preciousness to stand at the altar of our good Shepherd! to see him bleeding there as the slaughtered priest, and then to hear his blood speaking peace to all his flock, peace in our conscience, peace between Jew and Gentile, peace between man and his offended Maker, peace all down the ages of eternity for blood-washed men. Abel is the first shepherd in order of time, but our hearts shall ever place Jesus first in order of excellence. Thou great Keeper of the sheep, we the people of thy pasture bless thee with our whole hearts when we see thee slain for us.
Originally from Bible Gateway: https://www.biblegateway.com/devotionals/morning-and-evening/